1. Field
The present application is directed to testing features related to the family of at least partially testable current interrupting devices and systems which include, without limitation, ground fault circuit interrupters (GFCI's), arc fault circuit interrupters (AFCI's), immersion detection circuit interrupters (IDCI's), appliance leakage circuit interrupters (ALCI's), circuit breakers, contactors, latching relays and solenoid mechanisms.
2. Description of the Related Art
The electrical wiring device industry has witnessed an increasing call for circuit breaking devices or systems which are designed to interrupt power to various loads, such as household appliances, consumer electrical products and branch circuits. In particular, electrical codes require electrical circuits in home bathrooms and kitchens to be equipped with ground fault circuit interrupters, for example. Presently available GFCI devices, such as the device described in commonly owned U.S. Pat. No. 4,595,894, use a trip mechanism to mechanically break an electrical connection between one or more input and output conductors. Such devices are resettable after they are tripped by, for example, the detection of a ground fault. In the device discussed in the '894 patent, the trip mechanism used to cause the mechanical breaking of the circuit (i.e., the connection between input and output conductors) includes a solenoid (or trip coil). A test button is used to test the trip mechanism and circuitry used to sense faults and a reset button is used to reset the electrical connection between input and output conductors.
Such types of devices must rely on a user to push the test button at some periodic interval and visually verify that the mechanism has disengaged the latch by looking at the reset button position. By pushing the test button, the user activates a supervisory circuit and creates an artificial ground fault in the differential transformer of the GFCI. This artificial ground fault is actually a current imbalance created by diverting current around the differential transformer. If properly operating, the GFCI senses the current imbalance and initiates a tripping pulse to disengage the latching mechanism.